The present invention relates to gravity filtration apparatus and in particular to a gravity water filtration system including an upper unfiltered water reservoir and a lower filtered water reservoir and further including an automatic fill assembly connected to a water supply source. The two reservoirs are at different elevations and are mated in an unsealed manner.
Typically, prior art water filtration devices consist of filter(s) having outer regions in working contact with the upper unfiltered water reservoir and the output core region of the filter is connected to the lower filtered water reservoir. A filter flange seal is installed between the upper reservoir and the filter output core to maintain fluid isolation between the upper and lower water reservoirs. These prior art water filtration devices, however, tend to allow an overflow condition of the filtered water between the mating surfaces of the two reservoirs during an overflow situation. This event may occur when excess supply water is contained in the system resulting in a spillover onto a counter or the like surface and waste of filtered water. Also, unfiltered water may be wasted, which may be equally significant to wasting filtered water during periods of dangerously low and limited water availability.
It is often difficult to operate available water filtration systems at the system's effective capacity. It may be noted that the fastest rate of water filter processing will occur as long as the top unfiltered water reservoir is full to the brim at all times. This condition is the design capacity, where design capacity is the maximum rate of output achieved under ideal conditions. The design capacity requires constant water flow rate through the system with the upper reservoir filled (input) to the brim at all times while the lower reservoir drains (output) at a flow rate equal to the upper reservoir fill rate.
Applicant's pending Non-Provisional patent application Ser. No. 13/942,852 filed Jul. 16, 2013, and Provisional Application No. 61/848,684 filed Jan. 9, 2013, which applications are incorporated herein by reference, disclose a gravity water filtration system enabling the operator to readily maintain optimum effective capacity (or ‘optimum effective’ maximum water weight) by observing the position of an indicator, a scale, or some portion of the system geometry. Once the water system weight is indicated at maximum, the operator may allow the system to achieve a steady state condition (equilibrium), where the filtered water level in the lower water reservoir will be at a maximum level, and the unfiltered water level in upper water reservoir will be at a minimum level. No water should be added to the upper water reservoir while the system water weight is at a maximum as spillover of filtered water will occur. As filtered water is drawn out of the lower reservoir, the indicated mass (water volume) is reduced accordingly, and supply water may be added into the system until the maximum system water weight is again achieved.
Maintaining optimum effective capacity (or maximum water weight) of available water filtration systems is difficult because such systems may contain only supply side upper primary filter(s), or alternatively they may contain upper primary filter(s) used in conjunction (in series) with lower secondary filter(s), all having different diameters, shapes, volumes, and filter saturation conditions thus making visual interpretation of system water weight virtually impossible.